[rich.g.williams]

This is very interesting, I have seen gerke-decoder mentioned on other forums and realise now that you wrote it back in 2020. Mathematically it very interesting with the integration approach. Have you experimented with cross-plotting interval times (on a test basis) to give a graphic representation? Do you assign a statistical probability to dots, dashes, spaces?

I only started receiving SAQ last year and when I did my first decode was reading the screen and using pen and paper to work out each letter. This last decode on Alexanderson day was faster, perhaps because I knew what was coming and could guess what words were after two or three letters.

As I understand it (and have read), that to turn on and turn off transmission of the 17.2 kHz carrier takes time so SAQ so as you mentioned previously “the intention was to send at 15 WPM then the early transmission was an amazing accomplishment” !!

In the old days (I’m talking about the 1960’s) Short wave radio was used extensively, Morse speeds could get quite high even over 15 WPM. I think 20 WPM was not uncommon.

I was really interested in amateur radio and wanted to get a licence but passing the RSGB Morse test was a problem for me. As a young teenager there was getting to the exam, there was how to practice. I felt that I would never learn to transmit and receive Morse at the 12 WPM needed for the exam – so regretfully I left it back then and got interested in sound systems and microprocessors instead.

[rich.g.williams]

“Would you dare driving an old-timer ralley with a modern Formula-1 racing car ? Certainly not !
Receiving an old-time transmitter with a soundcard and a PC or an SDR is as well improper style or even bad taste, but in no way a remarkable achievement.
Everybody can do so !”

This is a very unfair comment I say this for the following reasons:

– The original Kungsbacka Receiver Station, it is noted that the Receiver antenna “consisted of two copper wires set up on 9 m tall telephone poles along a stretch of about 13.4 km, over Kungsbackaån and southeast out through Hanhals and Fjärås parishes to Skärsjön on the south side of Lygnern” So how many of us have access to such a 13.4 km length antenna.

– I want to receive SAQ transmission in Cardiff Wales UK and my garden allows for a 25 metre wire antenna so must use “every trick in the book” to receive SAQ with certainty at good signal strength.
– To build a simple tuned receiver modern electronics is easiest and to avoid need for hardware BFO etc its easy to record the 17200 Hz carrier directly using a Laptop PC (at 48 k samples/sec) and use software to detect the Morse code.

My belief is that the SAQ transmission propagates around the globe so for people trying to receive in the opposite hemisphere use of modern electronics and software processing is essential.

Also to be perfectly honest I have looked at some of the old receiver designs and to me they look very bloated, over complicated, difficult to understand and difficult to build – they do not follow the most important designers commandment which is “keep it simple”

I agree that existing receivers built originally should be looked after and kept safe but I do not agree that people should be encouraged to rebuild those old designs in the 21st Century.

[rich.g.williams]

I found this description of Kungsbacka Receiver Station https://www.radiomuseet.se/medlem/audionen2/nr4_2005/kung.html

also noted that the Receiver antenna “consisted of two copper wires set up on 9 m tall telephone poles along a stretch of about 13.4 km, over Kungsbackaån and southeast out through Hanhals and Fjärås parishes to Skärsjön on the south side of Lygnern”

[Author]

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